JPS6239633A - Rubber reinforcing material and production thereof - Google Patents

Abstract

PURPOSE:A reinforcing material, obtained by N-substituting and modifying the surface of a wholly aromatic polyamide fibers with an epoxy compound and forming a resorcin-formalin latex polymer layer and capable of exhibiting improved adhesive property to rubber. CONSTITUTION:A reinforcing material obtained by N-alkali metalating the surface layer of wholly aromatic polyamide fibers consisting of repeating units expressed by the formula -NH-Ar1-NH-CO-Ar2-CO- and/or -NH-Ar3-CO- (Ar1-Ar3 are bifunctional aromatic ring group, preferably >=80mol%, based on the total of Ar1, Ar2 and Ar3, p-phenylene group), reacting the surface layer with a compound having >=2 epoxy groups to carry out N-substituting modification and forming resorcin-formalin rubber latex polymer composition layer on the surface. Poly-p-phenylene terephthalamide is used as the wholly aromatic polyamide.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is characterized by a collapsed contact with rubber. Rubber reinforcing material NH shown
Regarding -CO-Ar2-CO- and its production method, see I':L in more detail.

The present invention relates to a rubber reinforcing material that exhibits excellent adhesion to specially derived rubber made of fully aromatic polyaminated fibers that exhibit desirable performance as reinforcing fibers for rubber and the like.

(Prior Art) Fully aromatic polyamide fibers not only have excellent heat resistance, but also para-oriented fully aromatic polyamide fibers are used as plastic reinforcement materials and industrial materials due to their high strength, high modulus, and physical properties. It has come to be widely used as an elastomer reinforcing material for materials, rubber, etc. In particular, as a composite material with elastomer, it is used for tires, various belts, hoses, rubberized cloth, etc.

When used in combination with these rubbers, the fibers are treated in advance with an initial condensate of resorcinol-formalin and boraratex (hereinafter referred to as F/L), and then embedded in the rubber. However, with polyester and wholly aromatic polyamide, RF/L treatment alone is not enough.
The adhesion between the L layer and the fibers was poor, and for this reason, the properties of the fully aromatic boria dP fiber, which had a long-awaited advantage f', could not be utilized effectively.

For this reason, many proposals have been made with the aim of improving the adhesion. For example, as such a treatment agent, a part of the structure g of H Examples include those using halogenated phenol, human mixed benzoic acid, furfuryl alcohol, etc.; (1) those using the general formula) epoxy compounds, melamine compounds, incyanate compounds, etc., with a third base added thereto; Well done,
+ii) A two-stage treatment method is also known in which the material is first treated with a liquid containing epoxy resin/and aromatic polyinocyanate resin, and then treated with RF/L.

(Problems to be Solved by the Invention) However, in these post-attachment treatments, when im is peeled from the rubber composite material, peeling occurs on the surface of the mountain fibers, and the rubber layer adheres to the fibers. This is not the preferred method of destruction. In other words, the adhesive force between the fiber and the rubber is still insufficient.

(Means for Solving the Problems) The present inventors believe that the solution to these problems is as follows:
Based on the idea that this can be achieved by reliably introducing a large number of reactive active funds with F/L onto the fiber surface, after various studies, we have completed the present invention.

That is, the object of the present invention is to provide the general formula -NH-A r 1
-NH-CO-Ar -CO-NH-CO-Ar2-C
O- and /M9 are -NH-A r 3- ('!0- repeating unit (wherein Ar1, Ar 2, Ar5 are each independent [representing a divalent aromatic cyclic group) ) The surface of the fully aromatic polyamide P#E1 fiber is modified with a compound having two or more epoxy groups. This is achieved by a rubber reinforcing material characterized by a preformed layer of formalin rubber latex polymer composition.

This rubber reinforcing material is made by converting the surface layer of the fully aromatic polyamide fiber of this invention into an N-alkali metal, and then reacting it with a compound having two or more epoxy groups to undergo N-fit conversion modification. The resorcinol-formalin-rubber latex polymer assembly can be produced by impregnating the fully aromatic boria-P fibers with a solution containing the following.

The wholly aromatic polyamide used in the present invention is one in which at least 85 moles of amide bonds are obtained by processing an aromatic cyclic diamine or an aromatic cyclic dicarzenic acid component. As an example of its structure, poly-4,4'--,7
Aminobenz RyojiriP Terephthalamide, Polyparaphenylene-2,6-Natsutalic Amide)%1 Cobolinodiphenylene/4.4'(3,3'-dimethylbiphenylene)-Terephthalamide, Copolynoξ rough phenylene/2
, 5-pyridylene-tele-7thalamito, polyolnephenylenephthalamito, polymetaphenylenephthalamito
1 Polyparaphenylene phthalamide, polyorthophenylene phthalamide, polymethaphenylene isophthalamide P1 holino ξ rough phenylene isophthalamide P1 boliolone phenylene terephthalamide P1 polymethaphenylene terephthalamide, poly-1,5-naphthalene phthalamide AξF, poly-4,4'-diphenylene-ortho-phthalamine)-', t? l+ -1,4-naphthalenephthalamyl P1 holy-1,4-naphthalenephthalamyl',
71J-1) Compounds of the general formula 5-naphthalene 7-talamide, etc., NH-CO-Ar2-CO-, and compounds in which a part of the nitrogen nucleus of these aromatic diamines is replaced with a norogen, and furthermore, A part of the benzene nucleus of the aromatic diamine was converted into piperazine, 2,5-dimethylpiperazine, 2
Aromatic boria containing an alicyclic amine such as a compound substituted with t5-diethylpiperazine, or aromatic diamine 3,3'-oxydiphenylene cyamine, 3,4'-oxydiphenylene Ether groups such as diamines, alkyl groups, -8-, -8O2-, -0-, -
Aromatic polyamide P containing two phenyl groups bonded by groups such as NH-, or a copolymer of the above-mentioned aromatic polyamide P; Examples include rough ethylene terephthalamide ξ copolymer, poly-3,4' to oxydiphenyl nylene terephthalamide p/bono ξ rough ethylene terephthalamide P copolymer.

The manufacturing method of these wholly aromatic polyamides P is not limited in carrying out the present invention, and for example, the method of producing the corresponding diamine L and diacid chloride P Toyu et al., Japanese Patent Publication No. 35-1
It can be easily manufactured by using the low temperature solution polymerization method known from Japanese Patent No. 4399 and the like.

The obtained wholly aromatic polyamide P is soluble in organic solvents by a conventional wet or dry spinning method as described in the above publication;
Alternatively, it can be produced by the method disclosed in Japanese Patent Publication No. 42-815, but fully aromatic polyamide P with a VcN content of
, 4-1) General formula. These fibers are made of aromatic groups bonded at the 5-12, 6-position), and middle 2-loughenylene groups. By the method described in various publications such as No. 47-39458, fossa modulus fibers were prepared by ζ et al.
x! 7 can be manufactured. Incidentally, commercially available products include DuPont's Kevlar 29 and Kevlar 49 (Izuj,
It is also a trademark of the DuPont Company - polynoξ rough ethylene terephthalate (also known as fiber).

In addition, as a special wholly aromatic polyamide P, there is one in which several tens of moles of the norahenylene diamine fraction of borino ξ rough phenylene terephthalamine P is replaced with 3.4' to diaminodiphenyl ether, Tokuko Showa 54-43f51
It can be manufactured according to Publication No. 2 and others.

The diameter of the fibers used in the present invention ranges from several μm to several tens of μm, which can be obtained using ordinary spinning techniques. Fibers with a fiber diameter of 0.1 μm to several μm have a logarithmic viscosity [3d/
! =/1 or more /J' oriented aromatic polyamide Ft-(A
) component, polyamide with logarithmic viscosity 1f, 3d#/r or less)
It can be produced by a method of extracting the TBI component from a conjugate fiber of 1kiBlff (see Japanese Patent Laid-Open No. 183420/1983). Mayu, fiber diameter is approximately 50λ~C),
Fibers with a diameter of less than 1 μm can be obtained by dropping a #sulfuric acid solution of fully aromatic polyamin into water-soaked acetone under high-speed stirring, or into water or acetone under ultrasonic action [e.g. , Vol. 34, [1,29
(1977): J. Polym.

Sci, Polym, Phys, gd, , V
ol, 17 e 1) see general formula 5 (1979)].

Any form of the fibers can be used in the practice of the present invention, including short fibers, sly fibers, S-1 fibers, etc.
Any of spun yarn, long fibers, tow, twisted yarn coat P1 net knitted fabric, web, and nonwoven fabric can be used depending on the purpose.

In carrying out the present invention, it is essential to N-sodiumize the fiber surface layer in order to increase the reactivity of the amyl bond. A method of sodium conversion in the presence of -CO-Ar2-CO- and lithium, potassium, sodium, etc., a method of sodium conversion with an adduct of naphthalene and an alkali metal such as sodium, or a method of sodium conversion with an adduct of naphthalene and an alkali metal, such as sodium, In hexamethylphosphoramine (hereinafter referred to as MPA), an alkali metal, such as sodium or sodium hydroxide (hereinafter referred to as MPA), is added.
-CO-Ar2-CO- and/or HMP A
It can be carried out by known means such as a method of converting into sodium in the presence of a reactant with.

There are no particular restrictions on the temperature and time of the alkali metalation reaction, and in general VC, the reaction temperature is between about 10°C and the boiling point of the system, particularly preferably at 5°C and 10°C, and the n1 reaction time is also used. Approximately 1 second to 5 hours are appropriate, depending on the type of wholly aromatic polyester, the alkali gold layering agent, for example, the sodizing agent, the desired sodium chloride if, and the rubbers that are the characteristics of the present invention. This can be determined by taking into consideration various points such as adhesive strength with the material.

N-alkali metalized fully aromatic polyamide P fiber is
Next, the N-alkali metalated boria sY2 is immersed in a compound having two or more epoxy groups or a solution thereof in an atmosphere with few interferences such as water to deactivate the N-alkali metalated boria s Y2 to form a fully aromatic polyamide with epoxy groups. r The epoxy compound is warped on the surface layer of the fiber.

There are no particular restrictions on the N-substitution reaction temperature and time for this compound having two or more epoxy groups,
-y, the reaction temperature is between about 0° C. and the boiling point of the epoxy compound, particularly preferably between 20° C. and 1 CO° C., and the reaction time is also suitably about 1 second to 10 hours.

Compounds having two epoxy groups in this reaction can be used to form a fully aromatic IJA εp with at least one epoxy group.
2 is bonded by replacing VcN-, but it is possible that other epoxy groups are similarly N-substituted, or that they have reacted with other epoxy compounds, or that unreacted epoxy groups may be detected, and even in the case of j, the effect of the present invention can be exerted because it can be chemically bonded to the RF/L of the present invention.

Totally aromatic polyamide surface layer in which N-substitution reaction occurs,
It is a surface layer of about 1 μm at most of the fiber, and it is different in the sodation agent and the sodation layer.

Examples of the compound having two or more epoxy groups used in the present invention include butadiene dioxyl, 2-(
2,3-epoxypropyl) phenyl glycidyl ether, epoxy a hexene-3--,) epoxy P,
2.6-(2,3-epoxypropyl)phenylglycidyl ether, siglycidyl ether, cyclopenta dienogicide, dipentene dioxai P1 triglycidyl isocyanurate, diglycidyl-5,5-dimethylhydantoin, chrycerin triglycidyl ether Etc. molecule epoxy compound, NH-CO-Ar2-
CO- and bisphenol A type epoxy resins represented by the formula (wherein 10 is a positive integer), the general formula (where n is 0
or an integer of +H), a polyglycol-type epoxy resin represented by the general formula (wherein R is an alkyl group, and n is 0 or a positive integer), or a cresol novolac-type epoxy resin, bisphenol. High molecular weight epoxy compounds such as F type epoxy resin, triglycidyl-p-aminophenol type epoxy resin, polynuclear phenol/glycidyl ether type epoxy resin B type, tetraglycidyl methylene dianiline type epoxy resin, triazine type epoxy resin etc. I can give up.

Next (8, after the above treatment, the fully aromatic polyamide in
The fiber is subjected to F/L treatment to form a 1cRF/L1 combined composition # on its surface, where RF/L is a mixture of an initial condensate of resorcin and formalin and rubber latex. As such, a conventional composition used for adhesion between ordinary fibers and rubbers is also used, and the molar ratio of resorcin and formaldehye P is 1: n, s ~
8. It is preferable that the solid content/weight ratio of Zorcin e-formalin and rubber latex is in the range of 1:3 to 1:20. If the above range is exceeded, the adhesive performance of the treated fiber material tends to decrease. Examples of the rubber latex used include natural rubber latex, styrene, butadiene copolymer latex, styrene butadiene terpolymer latex, nitrile rubber latex, neoprene latex, etc. Use alone or in combination. Among these, the use of vinyl-pyridine methylene e-butashev and terpolymer latex alone or in combination in half or more shows the best f'L friend performance.

The F/L polymer composition layer formed on the fully aromatic polyamide fibers does not need to be formed on all surfaces of each single fiber that takes over the fiber bundle, but at least The surface should be almost completely covered by Vc. Further, the amount of this F/L polymer composition layer is not particularly limited, and is approximately o,
The object of the present invention can be achieved as long as there is a 5-fold fit or more. There is no particular upper limit, but the upper limit is about 30 weight.

(Effects and Operations of the Invention) When the method of the present invention is applied, a wholly aromatic polyester P'g! which is stronger than ever before! The adhesive force between the fibers and the rubber layer, and the positive aK for ζ, provide the adhesive force between the fibers and the rLF/L polymer W composition layer.

That is, as will be exemplified later with specific examples, in the past, in actual epoxy compounds, fully aromatic boria t
Compared to the treatment similar to the present invention in which R fiber is treated and then subjected to RF'/L treatment, the surface layer of fully aromatic polyamide P fiber is first formed into an N-alkali gold layer, and then two or more epoxy groups are formed. In the present invention, in which the treatment is performed with a compound having
Since the N of the group is activated by layering with alkali gold, the epoxy compound undergoes a high rate of reaction substitution, and the 10H group and epoxy group, which are reactive functional groups with F/L, are activated. Furthermore, upon N-alkali total polarization, the hydrogen bonds directed toward the fully aromatic 71 amide molecules are severed, the structure between polymer molecules is loosened, and the fiber surface layer swells. It is recognized that a reaction between the epoxy compound and the polymer or polymerization of the epoxy compound occurs within this layer, and the implantation of active functional groups as described above takes place with a kind of anchoring effect. Therefore, it is presumed that the above adhesive force can be obtained.

In addition, the epoxidized fiber of the present invention has a good affinity with the RF/L processing solution, so-called wetting property, so that it can be used for F/LM!
It is also considered to be a factor in the preferable adhesiveness.

As mentioned above, the rubber reinforcing material of the present invention has excellent adhesive strength on the surface of fully aromatic polyamin fibers, so the favorable reinforcing fiber properties of the fibers can be utilized in the rubber reinforced structure, resulting in high reinforcing effects. It is thought that it also offers advantages such as extended service life, improved fatigue resistance, and reduced amount of reinforcing fibers.

The rubber reinforcing material of the present invention can be used as a composite material with various types of rubber reinforcing materials, such as tires, belts, toothed belts, other power transmission belts, conveyor belts, hoses, etc. , rubberized cloth, etc., the features of the present invention are effective.

(Examples) Hereinafter, the present invention will be explained using Examples to further clarify the present invention, but it goes without saying that the scope of the present invention is not limited to these Examples.

Example 1 Sodium HyPride 1.25 ? was added and heated at 70°C for 40 minutes in a nitrogen stream to completely dissolve.
Cooled to 5°C.

1) of polyparaphenylenetere 7 talamide fiber (Kevlar 49, DuPont trademark) with a length of 15 bacteria and a width of 10 cm.
General formula 407'neel yarn, 17 lengths and widths/
A woven fabric with a plain weave structure having a fiber density of 25 mm was added to the above DMSO system, and a 7+1 mm formation reaction was performed at 35° C. for 10 seconds. Next, DMS05CO and bisphenol type epoxy resin (DJ:, R.

383, Dow Chemical Company) 50v and 70λ, add 1! ! Crush and heat at 50℃ for 30
Allowed to react for minutes. The woven fabric was washed five times with a large amount of amethane to remove unreacted epoxy resin, and then dried under vacuum.

Next, the mixture was prepared in a manner similar to the arrows, immersed in fcRF/L processing solution, squeezed out with a mangle, dried at 150°C for 3 minutes, then dried at 180°C for 2 minutes, and then dried at 180°C for 2 minutes. 230
℃, apply a 2 minute cure ring.

At this time, the amount of the RF/L polymer composition adhered to the fiber was 9
, Double it! And 7ft.

(RF/L treatment agent formulation) Resorcinol 1) General formula. oM
t part water
238.4 Formalin (37X aqueous solution) 16.2 NaO
H1) General formula, 3 styrene/phtadiene/hinylj, total of 7
509.9 parts by weight Next, the treated fabric and an unvulcanized rubber sheet with a thickness of about 0.7 tm were combined and heated at 140°C x 15fn l using a pressure press.
n@vulcanized. The obtained sample was cut into 3cIR width and 1
Used in the 80° peeling method to measure the adhesion between rubber and fabric.

The set of rubber sheets used has already been used for a long time.

#1 (Natural Rubber) 701 Ikube Hiker #1502 (SBR Copolymer Rubber) 30 Carbon FEF 50 Stearin #2.0 Aromatic Softener
10 zinc white
5.0 Anti-aging agent ATV
1.5 Vulcanization accelerator DM 2.0 Total 173 parts by weight The peel strength between rubber/fabric is Fi6.6 kq, and the peel is a dark brown color of RF/Li combination? Even when observed under a stereoscopic microscope, no fibers were exposed at all, and it was confirmed that peeling occurred between the R, F/L composite composition and the rubber.

Comparative Example 1 Sodification treatment of the present invention NH-CO-Ar2-CO-
Example 1 was repeated in exactly the same manner for nine t-a soybeans treated with an epoxy compound. FLF attached to fiber/
The amount of the L-polymer composite sole layer was 7.3% by weight based on the weight of the fibers, and in Example 1, it can be seen that one of the effects of the present invention is that it has good elasticity with the processing liquid.

The peel strength was 2.9 kg, less than half that of Example 1, and the color of the fibers on the peeled surface was yellowish brown due to RF/L contamination, and even when observed under a stereomicroscope, the fibers were clearly exposed. et nf
c.

Bikinu Example 2 and Example 2 The Kevlar fabric used in Example 1 was not subjected to the treatment of the present invention, but was subjected to epoxy treatment 1, which is a conventional method, and then subjected to l'LF/L treatment in the same manner as Example 1. After that, the adhesive force with the rubber was measured.

Here, the epoxy treatment liquid prescription is as follows,
After immersing the woven fabric in the liquid CC, it was heat treated at 240C for 3 minutes.

(Epoxy treatment liquid formulation) Catalyst 95 2.0% by weight (Teikoku Kagaku, water # injection epoxy resin) NaOHO, 1 Perex OTP (5!' (solnl)
'1.0 water
95.9 total
101) General formula. 01 Fubu peeling force is 2.8 squares,
showed only the same value as Comparative Example 1.

On the other hand, using this two-stage treatment method of epoxy treatment and F/L treatment, the Tomo Kevlar woven fabric subjected to the treatment of the present invention in Example 1 was treated in exactly the same manner as above, and the peeling force was measured. , 5
．． 0 ky, and in this case as well, the effect of the present invention is remarkable, but the results are comparable to those of Example 1, or even worse. It has been proven that the two-stage treatment of epoxy treatment and RF/L treatment, which has been recommended for conventional wholly aromatic polyamide IR and WA fibers, is completely unnecessary and has a far superior cooling effect.

The difference in this effect is that in both cases, the fully aromatic polyamide fibers are treated with an epoxy resin prior to the RF/L treatment, but in the example of the present invention, the N-sodiumated fibers are treated with an epoxy resin. While the activity of the group N toward the nucleophilic reagent is low, in the conventional method, the activity of the group N of the wholly aromatic polyamide P is low, and most of the epoxy resins are probably , one NH2 group or one CO which is the terminal group of the molecule
It is inferred that this is because it only reacts with 0H groups and there are fewer covalent bonding points.

Example 3 Fabric of polymetaphenylene inophthalamide spun yarn (Tijin Co., Ltd.), tetrahyplofuran solution of naphthalene-sodium adduct (sodium tllIf1)
) In the general formula t(ft), after treatment at 35°C for 3 minutes, 50% of the same epoxy resin as in Example 1 was added to a 1:2 (volume ratio) mixture of dimethylsulfoxy P and dioxane 5CO-.
? The sample was immersed in a solution in which the sample was dissolved and treated at 45°C for 60 minutes.

After washing this woven fabric with a large amount of acetone, a F/L layer was formed in the same manner as in Example 1, and the peeling force from the rubber was determined.

The amount of the RF/L polymer composition adhered to the fiber was 12M, the peeling force was 6.5, and the peeled surface had a rubber color.
No exposed fiber surface was observed.

In comparison with Example 1, in this example, the yarn forming the groove bottom of the cloth is
Although the short fibers on the fabric surface are considered to have an anchoring effect on the R and FL layers, the fact that the peeling force is almost the same as in Example 1 means that the present invention Both sides of this are not due to peeling of the fiber surface, but due to F/L.
The layered appearance indicates that the destruction occurred in the rubber layer.

,・ゝ・.

Agent Mizu Ueki, 1 ;、Man・、(・

Claims (6)

[Claims] (1) General formula -NH-Ar_1-NH-CO-Ar_2
The surface of a fully aromatic polyamide fiber consisting of repeating units of -CO- and/or -NH-Ar_3-CO- (in the formula, Ar_1, Ar_2, and Ar_3 each independently represent a divalent aromatic cyclic group) A rubber reinforcing material characterized in that it is N-substituted and modified with a compound having two or more epoxy groups, and a resorcinol/formalin/rubber latex polymer composition layer is formed on the surface of the wholly aromatic polyamide fiber. . (2) Claim 1, in which about 80 mol% or more of the total of Ar_1, Ar_2, and Ar_3 is a paraphenylene group.
Rubber reinforcing material as described in section. (3) The rubber reinforcing material according to claim 1, wherein the wholly aromatic polyamide is polyparaphenylene terephthalamide. (4) General formula -NH-Ar_1-NH-CO-Ar_2
Surface layer of fully aromatic polyamide fiber consisting of repeating units of -CO- and/or -NH-Ar_3-CO- (in the formula, Ar_1, Ar_2, and Ar_3 each independently represent a divalent aromatic cyclic group) to N-alkali metallization,
Next, after reacting with a compound having two or more epoxy groups to undergo N-substitution modification, the fully aromatic polyamide fibers are impregnated with a liquid containing resorcinol/formalin/latex, and the surface of the wholly aromatic polyamide fiber is coated with resorcinol/formalin/rubber latex. A method for producing a rubber reinforcing material, comprising forming a polymer composition. (5) Claim 4, wherein about 80 mol% or more of the total of Ar_1, Ar_2, and Ar_3 is a paraphenylene group.
Method for manufacturing the rubber reinforcing material described in Section 1. (6) The method for producing a rubber reinforcing material according to claim 4, wherein the wholly aromatic polyamide is polyparaphenylene terephthalamide.